Retrieval devices may be used to retrieve objects, such as stones, from a subject's body. Commonly, such retrieval devices may include baskets or forceps for grasping objects. A basket may be introduced into a target area of a subject's body while in a contracted state, and may be expanded near an object targeted for retrieval. The expanded basket may be maneuvered to guide the object through a space between legs of the basket. For example, the expanded basket may be used to press the object against a wall of a body lumen, causing the object to force basket legs apart and thereby allowing the object to enter an interior region of the basket. In some instances, however, forcing the object against the wall may damage tissue at the point of contact.
In some instances, the presence of the object in the basket may cause the basket to remain at least partially expanded such that a diameter of the basket may exceed a diameter of a body lumen or opening at or near the target area. This may block withdrawal of the basket and the object from the subject. In such cases, release of the object from the basket may be a prerequisite for withdrawal of the basket from the subject. However, even if the basket is put in its expanded state, the object may be so large that it may not exit from the basket without intervention. Thus, additional procedures and/or devices may be required to free the object from the basket.
Grasping forceps also may be used to grasp objects in a subject's body. The forceps may include prongs that may be deployed to engage and grasp an object. The prongs may damage tissue near the site of the object. Even after the object is captured, the object may be pulled or pushed out of the forceps during withdrawal of the forceps from the subject's body.
Therefore, it may be useful to provide devices with enhanced capabilities, thereby providing ease of retrieval and/or release of an object from within a retrieval assembly.